Add/expose metrics in Prometheus for MachineConfigOperator

Customer like to have in Prometheus some metrics of MachineConfigOperator. For each MCP:
    
    - Paused
    - Updated
    - Updating
    - Degraded
    - Machinecount
    - ReadyMachineCount
    - UpdatedMachineCount
    - DegradedMachineCount
   

Why does the customer need this? (List the business requirements here)

These metrics would be really important, as it could show any MachineConfig action (updating, degraded, ...), which could also even trigger an alarm with a PrometheusRule. Having a dashboard of MachineConfig would be also really useful.